Pressure-gage.



No. 731,585. PATEN'I'ED JUNE 23, 1903.

c. J. MANNING.

PRESSURE GAGE.

APPLICATION FILED FEB. 5, 1903.

. N0 MODEL,

1o y Bourdon tubular spring for actuatingthe indicating mechanism; andthe object of the Patented Ju'ne 23, 1903 PATENT OFFIC COLEMAN J.MANNING, or MEDFORD, MASSACHUSETTS.

PRESSURE-GAGE.

srEcmmAT'IoN forming partof Letters Paten to. 731,585, dated June 23,1903.

Applicationfiled February 5, 1903:. Serial No. 141,965. (No model.)

To all whom it may concern:

and useful Improvement in Pressure-Gages,of which the following is aspecification.

My invention relates to pressure-gages for steam-boilers and. analogoususes, and is an improvement upon suchgages as employ the invention is tomake such spring-action more reliable and is attainedby the constructionhereinafter fully described, and illustrated in the accompanyingdrawings, in which- Figure l is a plan of the interior of apressure-gage embodying my improvement, showing also the index and asmall portion of the dial. Fig.2 is a section of the free ends of theBourdon tubular springs shown in Fig.

l and plan ofa portion of the connecting devices. Fig. 3 is'a section ofthe socket or steam-inlet and'a portion of the tubular spring attachedthereto. Fig. 4 is a crosssection of the tubular springs, taken as online 4 4, Fig. 2; and Fig. 5 is aperspective of one of the couplings foruniting the ends of thesprings.

The principal parts comprised in the pressure-gage, as illustrated,consist of the case A, dial B, (only partly shown,) index D, group ofmechanism D, called the index movement, the socket or inlet E, and twoBourdon tubular springs, which serve to actuate the index and of whichthe primary .one, F, is firmly attached to the socket of the inlet-pipe,and the secondary one, F, is coupled to the free ends of the tube F bycoupling connections G and G, as shown in Figs. 1

A and 2.

ment D. A

The gage illustrated in Fig. 1 is of the kind known as a steam-pressure)gage. Such gages as hitherto constructed have employed only asingleBourdon spring. In their practical use in connection withlocomotive-boilers they are subject to extremes of heat and cold and tomuch jarring, which deranges A come set, and thus impairs the actuatingvibration of its ends and renderits indications variable and unreliable.This is a serious defect in such gages as employ butone Bourdon spring,and much effort hasbeen made to overcome itby various devices,butwithout success. I have now, after muchexperimenting and study of theproblem, discovered. that by the employmentof an additional tubularspring F, open to the inlet of steam through the outer spring F andconfined only by the movable coupling connections G and G, by which itsends are joined to the ends of spring F, leaving its elasticity perfectfreedom of action from end to end of the spring, that it reinforces theprimary spring and overcomes the objection above referred to." Thecouplings G and G have interior channels H and H, which communicate withthe interiors of ,thetubular springs through holes I-and 1 in the ribswhich are inserted in the ends of the springs, as shown in Fig. 2. Thesteam passes through inlet E into the primary spring F at F and thencein both directions to and through the couplings G and G into theseconday spring F, thus operating with equal pressure on both springs,so both springs are vibrated in unison and equally, and by the greaterfreedom of vibration of thesecondary spring F it has no tendency tobecome set, such as the confined primaryspring F has, and consequentlyaids the latter 'in overcoming its tendency to set, for the reasonsalready explained, and causes perfect action of the index through themechanism D and gives correct indications of the pressure at all times,and this secondary spring F also stops the tremulous or fluctuatingvibration which the primary spring F has when used alone in a gageemployed on a locomotive and which causes a vibratory agitation of theindex that confuses the reading of the dial indications. The spring Fbeing unrestrained at all points except at its ends, as before stated,counteracts to some extent the vibratory action of the primary spring,and thus produces a steady vibratory movement of the two springs,according to the varying pressure, and so prevents the confusingfluctuations of the index referred to. Another .very desirable featurein this double-spring gages so employed, and such presence of water inand open communication between springs F and F has advantages in extremecold in preventing the bursting of pipes by freezing.

The couplings G and G have arms G and G the outer ends of which arerespectively pivoted to links G and Gflwhich are united in a movablehead G, not directly attached to the case and connected through link Gto the index movement D,as shown, and through which mechanism thevibratory motion of the springs is imparted to the index I) in thewell-known manner.

I claim- 1. In a pressure-gage, the combination of two Bourdon springsfor actuating the index movement, both ends of the primary spring beingfree to vibrate, while the body is open and intermediately secured tothe inlet device; and the secondary spring having its ends coupled withthe ends of the primary spring, and being supported thereby; allsubstantially as and for the purposes specified.

2. Ina pressure-gage, the combination of two Bourdon springs foractuating the index movement, both ends of the primary spring being freeto vibrate, whilethe body is open and intermediately secured to theinlet device; and the secondary spring having its ends coupled with theends of the primary spring, and so arranged in relation thereto that thespring and couplings will fill with water from condensation of thesteam, and contain the same; all substantially as specified.

3. In a pressure-gage, the combination of two tubular springs arrangedwith their four ends free to actuate an index mechanism, and havingtheir vibratory ends united by couplings having internal channelsthrough which the steam passes from one tube to the other,

substantially as specified.

COLEMAN J. MANNING.

Witnesses:

MAXWELL T. SMITH, EUGENE I-IUMPHREY.

